The Cook County Medical Examiner's office confirmed Monday night that it had received 18 human specimens that were found at O'Hare International Airport on Monday.
Sources said the specimens are human heads, still covered in skin and wrapped in plastic.
Sources tell FOX 32 News that they came from Italy, and may have been sent to be used for some kind of scientific research or a medical experiment.
Authorities said no foul play was suspected. U.S. Customs and Border Protection were investigating but declined to comment Monday night.